setup_network_bgp.md

Setup virtual switch/router (vyos)

Install vyos

wget https://downloads.vyos.io/release/1.1.8/vyos-1.1.8-amd64.iso

create -f qcow2 /home/admin/KVM/vyos.qcow2 20G

virt-install --virt-type kvm --vcpu 2 --name vyos --ram 2048 \
  --disk /home/admin/KVM/vyos.qcow2,format=qcow2 \
  --network network=default   --graphics vnc,listen=0.0.0.0 \
  --noautoconsole   --os-type=linux --os-variant=centos7.0 \
  --cdrom=/home/admin/KVM/vyos-1.1.8-amd64.iso

Add an internal interface to vyos

virsh attach-interface --domain vyos --type network \
  --source internal1 --model virtio  \       
  --mac 52:54:00:e2:75:cd --config --live

View a network

Each network is attached to a bridge

virsh net-dumpxml default

<network>
  <name>default</name>
  <uuid>dda581c1-9707-40ef-9eb5-9392525d733e</uuid>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:7c:9a:c3'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254'/>
    </dhcp>
  </ip>
  <ip family='ipv6' address='fd41:4f6e:a27a:c6f0::1' prefix='64'>
    <dhcp>
      <range start='fd41:4f6e:a27a:c6f0::10' end='fd41:4f6e:a27a:c6f0::ff'/>
    </dhcp>
  </ip>
</network>

Edit a network (like add a new IPv6 address)

virsh net-edit default

restart the network

virsh destory default
virsh create default

As we can see in the above XML the network type is NAT and the bride it is connect to is virbr0

View the the bridge

brctl show

View the IP and bridge configuration of a virtual machine

virsh domifaddr vyos

 Name       MAC address          Protocol     Address
-------------------------------------------------------------------------------
 vnet0      52:54:00:e2:75:cc    ipv6         2001:db8:ca2:2:1::cd/64
 -          -                    ipv4         192.168.122.156/24
 vnet1      52:54:00:e2:75:cd    ipv6         fd00:dcac:faa4:34::16a/64